In the replacement of degenerative natural tissue with a tissue prosthesis, care needs to be taken to damage surrounding bodily structures as little as possible so as to minimise trauma and to assist in reducing healing time.
An example where a tissue prosthesis is used is in the replacement of a nucleus of an intervertebral disc. An intervertebral disc comprises two parts, an annulus fibrosis surrounding a nucleus pulposus or nucleus. The intervertebral disc cooperates with end plates of the vertebrae between which it is sandwiched.
Various techniques have been proposed for dealing with age or injury related intervertebral disc degeneration. Two techniques in use are disc removal and fusion. Both of these techniques involve major invasive surgery with the related risks. More recently, another technique employed has involved the replacing of a degenerative disc with an artificial disc. This, once again, is carried out using major invasive techniques. Still more recently, techniques have been proposed to replace only the nucleus of the disc in circumstances where the degeneration is detected at a sufficiently early stage. Such techniques may be able to be performed in a minimally invasive manner.
A need exists when doing minimally invasive replacement of degenerative tissue with a prosthesis to cause as little trauma to surrounding bodily structures of the disc as possible.